This invention relates to an electrochromic mirror etc., which is used as an antiglare mirror for an automobile interior mirror or exterior mirror, and particularly to a sealing mechanism etc. for a solid type electrochromic antiglare mirror.
FIG. 3 shows a construction of a conventional usual electrochromic mirror. In this figure, numeral 11 is a flat, transparent substrate glass having a transparent conductive film 12, a solid type electrochromic layer 13 and a film 14 serving as an electrode and reflecting film such as an aluminum-made film formed on the back surface thereof on this order. The solid type electrochromic layer 13 has a construction of three-layers, comprising an oxidizing chromic film 13a, such as iridium oxide (IrOx), a solid electrolyte film 13b, such as tantalum pentoxide (Ta2O5), and a reductive chromic film 13c, such as tungsten trioxide (WO3). By the application of voltage between the transparent conductive film 12a and film 14 serving as an electrode and reflecting film (transparent conductive film 12b), the oxidizing chromic film 13a and the reductive chromic film 13c are simultaneously colored due to the reduction oxidation reaction, which decreases an incident light to and the reflected light on the film 14 serving as an electrode and reflecting film, thereby lowering the reflectance of the mirror and gaining an antiglare function. Also, by applying a voltage with reverse direction to the above voltage, the oxidizing chromic film 13a and the reductive chromic film 13c are simultaneously discolored due to the reduction oxidation reaction to be in the usual reflection stage with no lowered reflectance.
The solid type electrochromic layer 13 and the film 14 serving as an electrode and reflecting film are totally sealed by sealing resin 15 from their back surface sides including their back and side surfaces, and the back surface of the sealing resin 15 is further adhered to a sealing glass 16. The sealing glass 16 possesses a function to support the electrochromic layer 13 and the film 14 serving as an electrode and reflecting film sealed by the sealing resin 14 from their back surfaces through its mechanical strength, and a protective function to improve water proofing property, resistance to moisture permeability, corrosion resistance, etc. Furthermore, the sealing glass 16 has an ion-interrupting function which interrupts the movement of ions to prevent proton H+ (H+) and OHxe2x88x92 ion existing in constant amounts in the electrochromic layer 13 and bringing out coloration and discoloration from being discharged out (diffusion) and to prevent moisture and ions from entering in the electrochromic layer 13 whereby the coloration and discoloration reactions in the electrochromic layer can take place in a normal manner.
As described above, the electrochromic layer 13 exhibits its chromation reaction due to the moisture (including H+ ion and OHxe2x88x92 ion) existing in its film, high durability against environmental changes such as high temperature and high humidity conditions cannot be obtained on a practical level unless the moisture content in the electrochromic film is stabilized. For this reason, high durability on a practical level is obtained by adhesion of the sealing glass 16.
Now, the electrochromic antiglare mirror having any other construction will be described.
Japanese Patent Laid-Open 2000-2895 concerns a sealing construction of a solid type electrochromic antiglare mirror, and is characterized in that the solid type electrochromic layer 13 and the film 14 serving as an electrode and reflecting film shown in FIG. 3 are covered with, sealed and protected by a resin film (typically modified epoxy resin) having an ion-interrupting function which interrupts the movement of ions, water proofing property, anti-humidity, corrosion resistance and no sealing glass 16 is required.
However, even if the modified epoxy resin is used as the sealing resin, the moisture content in the electrochromic film against the environmental changes such as high temperature and high humidity conditions cannot be stabilized to a level near the case of utilizing the sealing glass, and there is the problem that no durability and no reliability sufficient for responding the environmental changes cannot be obtained. In addition, such a technique requires a step for adhering of a rubber adhesive sheet or a plastic, posing a problem in terms of man-hours.
Japanese Patent Laid-Open 2001-33830, which is directed to construction for sealing an electrochromic mirror, etc., is characterized in that the electrochromic layer 13 and the film 14 serving as an electrode and reflecting film shown in FIG. 3 shown in FIG. 3 are covered with, sealed and protected by a silicone rubber having weatherability, humidity resistance, abrasion resistance, and heat resistance a prescribed member having water proofing property, anti-humidity, abrasion resistance and heat resistance such as a polymer film is provided on the back surface of the silicone rubber wherein a member having silicone rubber is utilized as said silicone rubber and said prescribed member in such a manner that the surface of the silicone rubber of the member having silicone rubber is adhered on the back surface and the side surfaces of the film 14 serving as an electrode and reflecting film so as to envelope the film. The outer circumference surface of the mirror from the substrate glass to the prescribed member is covered with a humidity proofing material.
However, even in the case where the silicone rubber is used as the sealing resin, the polymer film is provided on the back surface of the silicone rubber, and the outer circumference surface of the mirror is covered with the humidity-proofing material, the moisture content in the electrochromic film against the environmental changes such as high temperature and high humidity conditions cannot be stabilized to a level near the case of utilizing the sealing glass, and there is the problem that no durability and no reliability sufficient for responding the environmental changes cannot be obtained. In addition, such a technique requires a step for adhering of a rubber adhesive sheet or a plastic, posing a problem in terms of man-hours. In addition, since the silicone rubber surface of the member having silicone rubber is adhered, the reliability for adhesion is low.
As described above, in order to obtain durability and reliability against the environmental changes such as a high temperature and a high humidity on a practically sufficient level, the sealing glass must be used at the present situation. Furthermore, as shown in FIG. 4, the side portion of the electrochromic mirror should be doubly sealed by a fluorine type coating 5 and an anti-humidity material 6 such as a butyl tape. In FIG. 4, the numeral 1 indicates a substrate glass having a transparent conductive film, 2 is an electrochromic layer and a metal reflector, 3 is a sealing resin, and 4 is a sealing glass.
In addition, Japanese Patent Laid-Open No. 6-222398 relates to an electrochromic mirror, which utilizes a metal plate instead of the sealing glass 4 shown in FIG. 4. However, there is a problem concerning the requirement of adhering the metal plate similar to the above technique.
U.S. Pat. No. 5,448,397 is directed to an automatic side-view mirror and utilizes a sealing glass 4 as shown in FIG. 5, which remains the problem concerning reducing the weight.
As described above, an electrochromic antiglare mirror having no member corresponding to the sealing glass and having high durability and reliability against environmental changes such as a high temperature and a high humidity has not yet been provided on a practical level.
In the present invention, for example, as shown in FIG. 1, resin containing prescribed filler which can minimize a change in moisture content in an electrochromic film is used as a sealing resin, and an outer circumference is sealed by a silyl-containing polymer 9 whereby high durability and reliability against environmental changes such as a high temperature and a high humidity can be obtained, and a member corresponding to the sealing glass can be successfully eliminated from an electrochromic antiglare mirror having no member corresponding to the sealing glass for the first time.